The HMO Research Network, in collaboration with American Association of Health Plans (AAHP), is hosting the seventh annual HMO Research Network National Conference on April 24-25, 2001 in Seattle, WA. The HMO Research Network is comprised of the major public domain research centers situated in large health maintenance organizations, generally non-profit organizations. This national meeting provides a forum to advance the individual and collective research efforts of these organizations. The purpose of the conference is three-fold: 1) to provide a forum for the HMO researchers to discuss methods and to disseminate research findings from studies conducted in HMOs; 2) to create opportunities for researchers and staff working within HMO- based research centers to collaborate on multi-site research projects, with approaches that facilitate cross-site collaboration; and 3) to enhance the ability of the research centers participating in the HMO Research Network to respond to national goals to enhance the effectiveness, efficacy and overall quality of health care delivery systems; and to contribute to national research agendas and funding priorities. Support for this conference fosters collaboration among a set of established and productive research organizations that are able to conduct population-based research in large populations through their collaborative efforts. These collaborative efforts are proving to be a powerful force for addressing urgent issues in health and preventive care.